Chest wall reconstruction with 3-dimensional custom-made carbon fiber ribs

Trachea repair using an autologous pericardial patch combined with a 3D carbon fiber stent: A case report

This study is the first to use an autologous pericardial patch combined with a 3D carbon fiber stent for the plastic repair of a large trachea defect. Radical surgery is the optimal therapy for primary malignant tracheal tumors. Tracheoplasty or repair is required to guarantee trachea integrity and normal ventilation function after tracheal tumor resection. Here, we present a case of plastic repair of the trachea using an autologous pericardial patch and a 3D custom-made carbon fiber stent. A 4 cm trachea defect was successfully repaired after resecting a malignant schwannoma. The postoperative ventilatory function was normal without obvious symptoms of discomfort. Fiberoptic bronchoscopy showed a smooth mucosal surface of the endotracheal wall and patency of the airway. CT scans performed 3 years after surgery showed no recurrence. Therefore, we can conclude that a 3D carbon fiber stent is feasible for abolishing patch floating and preventing tracheal stenosis.

Functional design and biomechanical evaluation of 3D printing PEEK flexible implant for chest wall reconstruction

BACKGROUND AND OBJECTIVE

Rigid reconstruction of chest wall defect seriously affects the postoperative respiratory owing to neglecting the functional role of natural costal cartilage. In the study, a 3D printing PEEK flexible implant was developed to restore the deformation capability during breathing motion.

MATERIALS AND METHODS

Bionic spring structures in different region of implant were designed by taking into consideration of the anatomical morphology and materials properties of costal cartilage. The biomechanical properties of the rigid and flexible implants under the chest compression were compared through the finite element analysis. Two kinds of chest wall implant samples were fabricated with fused deposition modeling (FDM) technology to evaluate experimentally the mechanical behaviors. Finally, the restoration ability of respiratory function from the flexible implant was investigated in vivo.

RESULTS

The flexible implant exhibited the similar stiffness to the natural thorax and satisfied the strength demand in the chest compression. The maximal impact force of flexible implant reached to 536 N. The fatigue failure of complete flexible implant was revealed from the initiation and propagation of interlaminar crack to the fracture in a zigzag manner. Animal experiments validated that the parameters characterizing respiratory could be recovered to the preoperative and normal state.

CONCLUSIONS

In the study, the flexible implant provided these advantages for perfect replication of thoracic shape, reliable safety, and great deformation capability to response respiratory movement, which given a superior treatment for chest wall reconstruction.

Three-Dimensional-Printed Model as a Template for Chest Wall Reconstruction

BACKGROUND

To our knowledge, this is the first time that a three-dimensional (3D)-printed model was used as an intraoperative template to recreate the resected portion of the lateral chest wall after resection of a large chest-wall tumour.

METHODS

Fabrication of 3D-printed models requires collaboration among a surgeon, radiologist, segmenter, and 3D printing centre. Three-dimensional models are created with computed tomographic and magnetic resonance data. These models can provide an accurate guide for surgical resection and can be used intraoperatively as a template to construct tailored prostheses.

RESULTS

We achieved complete resection of the chest wall defect, restored skeletal function and physiologic chest excursion, and achieved the best cosmetic appearance in all cases.

CONCLUSIONS

Small- to medium-sized chest wall defects can be repaired with musculocutaneous flaps with or without prosthetic materials, but more complicated defects require increasingly sophisticated reconstructive techniques and technologies. An advanced technique is the use of a 3D-printed model of the chest wall as an intraoperative template.

Nanoparticle-modified chitosan-agarose-gelatin scaffold for sustained release of SDF-1 and BMP-2

Background

Stromal cell-derived factor 1 (SDF-1) is an important chemokine for stem cell mobilization, and plays a critical role in mobilization of mesenchymal stem cells (MSCs). Bone morphogenetic protein 2 (BMP-2) plays a critical role in osteogenesis of MSCs. However, the use of SDF-1 and BMP-2 in bone tissue engineering is limited by their short half-lives and rapid degradation in vitro and in vivo.

Methods

The chitosan oligosaccharide/heparin nanoparticles (CSO/H NPs) were first prepared via self-assembly. Chitosan-agarose-gelatin (CAG) Scaffolds were then synthesized via gelation technology using cross-linked chitosan, agarose, and gelatin, and were modified by CSO/H NPs. The encapsulation efficiency and release kinetics of SDF-1 and BMP-2 were quantified using an enzyme-linked immunosorbent assay. A CCK-8 assays were used to evaluate biocompatibility of NP-modified scaffolds. The biological activity of the loaded SDF-1 and BMP-2 was evaluated using the transwell migration assay and osteogenic induction assay. An animal MSC recruitment model was used to study the ability of SDF-1 released from NP-modified scaffolds to induce migration of MSCs.

Results

In this study, we developed a novel nanoparticle-modified CAG scaffold for the delivery of SDF-1 and BMP-2. CCK-8 assays demonstrated excellent biocompatibility of NP-modified scaffolds. In addition, we investigated the release of SDF-1 and BMP-2 from NP-modified scaffolds, and evaluated the effect of released SDF-1 on MSC migration. The effect of released BMP-2 on MSC osteogenesis was also examined. In vitro cell migration assays showed that SDF-1 released from NP-modified scaffolds retained its migration activity; osteogenesis studies demonstrated that released BMP-2 exhibited a strong ability to induce differentiation towards osteoblasts. Our in vivo recruitment assays showed continuous chemotactic response of MSCs to SDF-1 released from the NP-modified scaffold.

Conclusion

The simplicity of synthesizing CSO/H NP-modified CAG scaffolds, combined with its high cytokine loading capacity and sustained release effect, renders NP-modified CAG scaffold an attractive candidate for sustained release of SDF-1 and BMP-2 to promote bone repair and regeneration.